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P. Zou W.B. Zhang T. Lei J.K. Wang 《金属学报(英文版)》2006,19(5):341-346
A high temperature-tolerating thermoacidophilic archae (TA) was isolated from water samples collected from a hot sulfur-containing spring in the Yunnan Province, China, and was used in bioleaching experiments of a low-grade chalcopyrite ore. The TA grow at temperatures ranging from 40 to 80℃, with 65℃ being the optimum temperature, and at pH values of l.5 to 4.0, with an optimum pH value of 2.0. The bioleaching experiments of the chalcvpyrite ore were conducted in both laboratory batch bioreactors and leaching columns. The results obtained from the bioreactor experiments showed that the TA bioleaching rate of copper reached 97% for a 12-day leaching period, while the bioleaching rate was 32.43% for thiobacillus ferrooxidans (Tf) leaching for the same leaching time. In the case of column leaching, tests of a two-phase leaching (196 days), that is, a two-month (56 days) Tf leaching in the first phase, followed by a 140-day TA leaching in the second phase were performed. The average leaching rate of copper achieved for the 140-day TA leaching was 195mg/(L.d), while for the control experiments, it was as low as 78mg/(L .d) for the Tf leaching, indicating that the TA possesses a more powerful oxidizing ability to the chalcopyrite than Tf Therefore, it is suggested that the two-phase leaching process be applied to .for the heap leaching operations, whereas, the TA can be used in the second phase when the temperature inside the heap has increased, and the primary copper sulfide minerals have already been partially oxidized with Tf beforehand in the first phase. 相似文献
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The effects of different methods of application of chlortetracycline and oxytetracycline on microbial properties of lamb meat were studied. A significant antibacterial effect of antibiotic was found on total mesophilic bacteria count. The mesophilic bacteria level was determined by two methods: the conventional method using Plate Count Agar and bioluminescence. Correlation curves of the CFU and RLU values proved two methods were highly related. Thus for the microbiology quality of meat hygiene the bioluminescence method may be used as a fast and alternative method to PCA. Note that bioluminescence requires a higher degree of skill and attention. 相似文献
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P. Zou* W.B. Zhang Kunming University of Science Technology Kunming China T. Lei J.K. Wang Technology Center Yunnan Metallurgy Group Co. Ltd. Kunming China 《金属学报(英文版)》2006,(5)
1. Introduction There have been two difficulties encountered with the leaching of low-grade primary chalcopyrite oresusingmesophile culture-thiobacillusferrooxidans(Tf) and thiobacillusthiooxidans(Tt), and so on[1-3].The first is the poor leaching effect and the second is the resultant increase in temperature during the middle and the later phase ofheap-leachingperiod, which is unfavorable for the growth and the culture of Tf and Tt. Being widely used for mineral leaching at present, Tf and … 相似文献
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A high temperature-tolerating thermoacidophilic archae (TA) was isolated from water samples collected from a hot sulfur-containing spring in the Yunnan Province, China, and was used in bioleaching experiments of a low-grade chalcopyrite ore. The TA grow at temperatures ranging from 40 to 80℃, with 65℃ being the optimum temperature, and at pH values of 1.5 to 4.0, with an optimum pH value of 2.0. The bioleaching experiments of the chalcopyrite ore were conducted in both laboratory batch bioreactors and leaching columns. The results obtained from the bioreactor experiments showed that the TA bioleaching rate of copper reached 97% for a 12-day leaching period, while the bioleaching rate was 32.43% for thiobacillus ferrooxidans (Tf) leaching for the same leaching time. In the case of column leaching, tests of a two-phase leaching (196 days), that is,a two-month (56 days) Tf leaching in the first phase, followed by a 140-day TA leaching in the second phase were performed. The average leaching rate of copper achieved for the 140-day TA leaching was 195mg/(L· d), while for the control experiments, it was as low as 78mg/(L· d) for the Tf leaching, indicating that the TA possesses a more powerful oxidizing ability to the chalcopyrite than Tf. Therefore, it is suggested that the two-phase leaching process be applied to for the heap leaching operations, whereas, the TA can be used in the second phase when the temperature inside the heap has increased, and the primary copper sulfide minerals have already been partially oxidized with Tf beforehand in the first phase. 相似文献
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Achilleas D. Bouletis Ioannis S. Arvanitoyannis Christos Hadjichristodoulou Christos Neofitou Maria Sakkomitrou Foteini Kolokythopoulou 《International Journal of Food Science & Technology》2014,49(2):329-336
The aim of this work was to evaluate the effect of various atmosphere compositions (20% CO2/80% N2 for modified atmosphere packaging (MAP) 1, 50% CO2/50% N2 for MAP 2, 70% CO2/30% N2 for MAP 3 and vacuum packaging) on the microbial (mesophiles, psychrophiles, Pseudomonas spp., Brochothrix thermosphacta and Enterobacteriaceae), physical, chemical [trimethylamine (TMA) and total volatile basic nitrogen (TVBN)] and sensorial characteristics of broadtail squid (Illex coindetii) stored for 10 days at 2 ± 1 °C. All microbial populations were severely restrained by MAP 3 with the exception of Enterobacteriaceae, which seemed to take advantage of the lack of competitive microflora and had enhanced microbial counts on MAP samples (P < 0.05). Colour attributes were better maintained on MAP‐stored samples. Drip loss was less on vacuum‐packaged squids. MAP 2 was the best atmosphere for the preservation of tissue consistency. TMA and TVBN formation was limited by high CO2 atmospheres, even though both elevated in all studied conditions. Shelf life based on sensory characteristics was determined to be 10, 8, 6, 6 and 4 days for MAP 3, MAP 2, MAP 1, vacuum and control samples, respectively. 相似文献
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